U.S. patent number 10,680,488 [Application Number 15/574,576] was granted by the patent office on 2020-06-09 for in-vehicle drive device with cooling channels.
This patent grant is currently assigned to NISSAN MOTOR CO., LTD.. The grantee listed for this patent is NISSAN MOTOR CO., LTD.. Invention is credited to Hirofumi Shimizu, Nobuaki Yokoyama.
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United States Patent |
10,680,488 |
Yokoyama , et al. |
June 9, 2020 |
In-vehicle drive device with cooling channels
Abstract
A drive device of the present invention includes: an electric
motor including a cooling channel; a power conversion unit that
converts electric power from a power supply and outputs electric
power to be supplied to the electric motor; and a supporting member
fixed to the electric motor with the power conversion unit mounted
on the supporting member. The supporting member includes a cooling
channel connected to the cooling channel of the electric motor.
Inventors: |
Yokoyama; Nobuaki (Kanagawa,
JP), Shimizu; Hirofumi (Kanagawa, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
NISSAN MOTOR CO., LTD. |
Yokohama-shi, Kanagawa |
N/A |
JP |
|
|
Assignee: |
NISSAN MOTOR CO., LTD.
(Yokohama-shi, JP)
|
Family
ID: |
57319729 |
Appl.
No.: |
15/574,576 |
Filed: |
May 20, 2015 |
PCT
Filed: |
May 20, 2015 |
PCT No.: |
PCT/JP2015/064425 |
371(c)(1),(2),(4) Date: |
November 16, 2017 |
PCT
Pub. No.: |
WO2016/185575 |
PCT
Pub. Date: |
November 24, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180159403 A1 |
Jun 7, 2018 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K
5/20 (20130101); H02K 11/33 (20160101); H02K
9/19 (20130101); H02K 5/225 (20130101) |
Current International
Class: |
H02K
5/20 (20060101); H02K 5/22 (20060101); H02K
11/33 (20160101); H02K 9/19 (20060101) |
Field of
Search: |
;310/58 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102130542 |
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Jul 2011 |
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CN |
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103107629 |
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May 2013 |
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CN |
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19645635 |
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Apr 1998 |
|
DE |
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10 2010041589 |
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Mar 2012 |
|
DE |
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10 2011081511 |
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Feb 2013 |
|
DE |
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10 2012 218 444 |
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Apr 2014 |
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DE |
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3 203 614 |
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Aug 2017 |
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EP |
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2005-20881 |
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Jan 2005 |
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JP |
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2005020881 |
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Jan 2005 |
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JP |
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2006-174572 |
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Jun 2006 |
|
JP |
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2006-197781 |
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Jul 2006 |
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JP |
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2007-306741 |
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Nov 2007 |
|
JP |
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2011-147253 |
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Jul 2011 |
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JP |
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2011-167025 |
|
Aug 2011 |
|
JP |
|
2011-182480 |
|
Sep 2011 |
|
JP |
|
2013-188030 |
|
Sep 2013 |
|
JP |
|
20110083554 |
|
Jul 2011 |
|
KR |
|
WO-2013/042486 |
|
Mar 2013 |
|
WO |
|
Other References
Machine translation of JP 2005020881 A (Jan. 2005). (Year: 2005).
cited by examiner.
|
Primary Examiner: Andrews; Michael
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
The invention claimed is:
1. A drive device comprising: an electric motor including a cooling
channel; a power conversion unit that converts electric power from
a power supply and outputs electric power to be supplied to the
electric motor; and a supporting member on which the power
conversion unit is mounted, wherein the supporting member includes
a cooling channel connected to the cooling channel of the electric
motor, a power module of the power conversion unit includes a
cooling channel, a channel inlet, and a channel outlet, such that
cooling water flows from the cooling channel of the supporting
member into the cooling channel of the power module through the
channel inlet and returns into the cooling channel of the
supporting member through the channel outlet, the cooling channel
of the supporting member is formed inside the supporting member in
the shape of a groove-shaped channel extending back and forth in a
serpentine manner, and the cooling channel of the supporting member
connects the cooling channel of the electric motor and the cooling
channel of the power module.
2. The drive device according to claim 1, wherein an outlet of the
cooling channel of the supporting member is connected in direct
contact with an inlet of the cooling channel of the electric
motor.
3. The drive device according to claim 1, wherein the electric
motor is in a cylindrical shape, the supporting member is disposed
on a cylindrical outer periphery of the electric motor, and the
supporting member is fixed to a pedestal formed on the electric
motor at an outer side of the supporting member.
4. The drive device according to claim 3, wherein the supporting
member is disposed such that a space is provided between the
supporting member and the electric motor.
5. The drive device according to claim 1, wherein the supporting
member is fixed such that a surface thereof on which the power
conversion unit is mounted faces the electric motor.
6. The drive device according to claim 1, wherein the supporting
member is formed of an elastic body.
7. The drive device according to claim 1, wherein the supporting
member is fixed to the electric motor with an elastic body
interposed therebetween.
8. The drive device according to claim 1, wherein the supporting
member is disposed on a lateral side of the electric motor.
Description
TECHNICAL FIELD
The present invention relates to a drive device in which an
electric motor and a power conversion unit are formed integrally
with each other.
BACKGROUND ART
There has conventionally been proposed a structure for directly
cooling a power module by means of a cooling channel provided in
the outer periphery of an electric motor, and Patent Literature 1
has been disclosed as a rotating electric machine system with such
a structure. In the case of such a structure, electronic components
such as a sensor, a power module, and a smoothing capacitor are
directly fixed to a housing for the electric motor. Thus, it is
necessary to perform the mounting of the electronic components in
the process of manufacturing the electric motor. Moreover, it is
also necessary to perform steps of connecting busbars and attaching
harnesses in order to electrically connect the electronic
components in the process of manufacturing the electric motor.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Patent Application Publication No.
2011-182480
SUMMARY OF INVENTION
Technical Problem
Handling electronic components, however, requires significantly
more strict control of the inside of the manufacturing room than
handling mechanical components. Thus, manufacturing the
above-mentioned conventional rotating electric machine system has a
problem in that a step requiring measures against contamination and
static electricity is added to the process of manufacturing the
electric motor.
Thus, the present invention has been proposed in view of the
above-mentioned circumstances, and an object thereof is to provide
a drive device that enables prevention of addition of a step that
requires measures against contamination and static electricity to a
manufacturing process.
Solution to Problem
To solve the above-mentioned problem, a drive device according to
one aspect of the present invention includes: an electric motor
including a cooling channel; a power conversion unit that converts
electric power from a power supply and outputs electric power to be
supplied to the electric motor; and a supporting member fixed to
the electric motor with the power conversion unit mounted on the
supporting member. Moreover, this supporting member includes a
cooling channel connected to the cooling channel of the electric
motor.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exploded perspective view illustrating the structure
of an in-vehicle drive device according to a first embodiment of
the present invention.
FIG. 2 is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to the first embodiment of the
present invention.
FIG. 3 is a set of views illustrating the structure of a supporting
member of the in-vehicle drive device according to the first
embodiment of the present invention, part (a) of FIG. 3 being an
exploded perspective view and part (b) of FIG. 3 being a back
view.
FIG. 4 is an exploded perspective view illustrating the structure
of an in-vehicle drive device according to a second embodiment of
the present invention.
FIG. 5 is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to the second embodiment of the
present invention.
FIG. 6 is an exploded perspective view illustrating a structure of
an in-vehicle drive device according to a third embodiment of the
present invention.
FIG. 7 is an exploded perspective view illustrating a structure of
the in-vehicle drive device according to the third embodiment of
the present invention.
FIG. 8 is an exploded perspective view illustrating the structure
of an in-vehicle drive device according to a fourth embodiment of
the present invention.
FIG. 9 is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to the fourth embodiment of the
present invention.
FIG. 10 is a side view illustrating the structure of an in-vehicle
drive device according to a fifth embodiment of the present
invention.
FIG. 11 is a view illustrating an alternative structure of the
supporting members constituting the in-vehicle drive devices.
DESCRIPTION OF EMBODIMENTS
First to fifth embodiments employing the present invention will now
be described with reference to the drawings. Note that an
in-vehicle drive device will be described as an example of a drive
device in the embodiment.
First Embodiment
[Configuration of In-Vehicle Drive Device]
FIG. 1 is an exploded perspective view illustrating the structure
of an in-vehicle drive device according to this embodiment, and
FIG. 2 is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to this embodiment. As
illustrated in FIGS. 1 and 2, an in-vehicle drive device 1
according to this embodiment includes an electric motor 3, a power
conversion unit 5, and a supporting member 7.
The electric motor 3 is, for example, a three-phase AC synchronous
motor and its exterior shape is formed mainly by an electric-motor
housing 11, an end plate 13, and a top plate 15. Moreover, the
output shaft of the electric motor 3 is connected to a reducer
17.
A housing portion 19 that houses the power conversion unit 5 and
the supporting member 7 is formed in the electric-motor housing 11.
This housing portion 19 is a box-shaped housing case formed
integrally with the electric-motor housing 11 in an upper portion
of the electric-motor housing 11, and is configured to be sealed by
the top plate 15 with the power conversion unit 5 and the
supporting member 7 housed therein. Also, a cooling channel 21 is
formed in the outer periphery of the electric-motor housing 11, and
allows cooling water to flow therethrough to cool the electric
motor 3. The cooling water flows in from the supporting member 7
through an electric-motor channel inlet 23, circulates in the
entire outer periphery of the electric-motor housing 11 to cool the
electric motor 3, and then flows out to the outside of the electric
motor 3.
The power conversion unit 5 is an inverter formed of a power module
25 and a group of other electronic components, for example, a
current sensor, a smoothing capacitor, and a control board, as well
as busbars and harnesses connecting given components, and the like.
This power conversion unit 5 converts electric power from a power
supply and outputs electric power to be supplied to the electric
motor 3. Specifically, the power conversion unit 5 converts a DC
current supplied from a high-voltage battery for driving the
vehicle through a junction box into a three-phase AC current by
means of a power semiconductor device and supplies it to the
electric motor 3. This three-phase AC current is a current
corresponding to a target torque at the frequency synchronized with
the number of motor revolutions, and is generated by switching a
semiconductor switching element by means of a PWM signal. Note that
although a case where the power module 25 in the power conversion
unit 5 includes a cooling channel will be described in this
embodiment, neither the power conversion unit 5 nor the power
module 25 may include a cooling channel.
The supporting member 7 is a member configured to be fixed to the
electric-motor housing 11 of the electric motor 3 with the power
conversion unit 5 mounted on its upper surface, and is, for
example, a casting cooler. The supporting member 7 includes a
cooling channel 27 configured to be connected to the cooling
channel 21 of the electric motor 3, and this cooling channel 27 is
formed inside the supporting member 7. As illustrated in FIG. 3,
the supporting member 7 is formed in a flat plate shape and has a
subassembly structure with the power conversion unit 5 mounted on
its upper surface. Also, recessed spaces are provided over the
entire back surface of the supporting member 7, and form the
cooling channel 27 by being sealed by the bottom plate 29. Provided
with partitions in a staggered manner, the cooling channel 27 is in
the shape of a groove-shaped channel extending back and forth in
the left-right direction. However, the shape of the cooling channel
27 is freely changeable by changing the arrangement of the
partitions, and also the partitions may not be provided.
Alternatively, as illustrated in FIG. 11, the supporting member 7
may be formed of a channel board 51 and a supporting board 53. The
channel board 51 and the supporting board 53 are joined by welding
or the like into one piece. Recessed spaces similar to those in
FIG. 3 are provided over the entire back surface of the channel
board 51, and form a cooling channel 27 by being sealed by the
supporting board 53. While the bottom plate 29 illustrated in FIG.
3 is a thin plate for sealing, the supporting board 53 in FIG. 11
has a thickness not only for sealing but also for ensuring
strength. Thus, the thickness of the supporting board 53 may be,
for example, equal to the channel board 51 or greater than the
channel board 51. However, the entire thickness is the same between
the supporting member 7 illustrated in FIG. 3 and the supporting
member 7 illustrated in FIG. 11. Hence, although the entire
thickness is the same, the supporting member 7 illustrated in FIG.
11 has higher strength.
The cooling water flows in from a supporting-member channel inlet
31, flows back and forth in the left-right direction through the
cooling channel 27, and flows into the power module 25 from the
power-module channel inlet 33 near the center of the supporting
member 7. The cooling water having flowed through the power module
25 returns into the cooling channel 27 from a power-module channel
outlet 35, flows back and forth in the left-right direction through
the cooling channel 27 again, and then flows out of the supporting
member 7 through a supporting-member channel outlet 37. The cooling
channel 27 of the supporting member 7 and the cooling channel 21 of
the electric motor 3 are connected by a connecting pipe 39. The
cooling water flowing out of the supporting member 7 flows into the
electric motor 3 and used to cool the electric motor 3. Note that
the supporting member 7 illustrated in FIG. 11 has a structure
similar to the supporting member 7 in FIG. 3, and the cooling water
thus flows in a similar manner to cool the electric motor 3.
Here, the power-module channel inlet 33 and the power-module
channel outlet 35 in the supporting member 7 are openings provided
in accordance with the position of the cooling channel in the power
module 25. Thus, if the position of the cooling channel is changed
due to a change in structure of the power module 25, the positions
of the power-module channel inlet 33 and the power-module channel
outlet 35 are also changed in accordance with the changed position
of the cooling channel in the power module. Likewise, if the
position of the electric-motor channel inlet 23 is changed due to a
change in structure of the electric motor 3, the position of the
supporting-member channel outlet 37 is changed in accordance with
the position of the electric-motor channel inlet 23.
In conventional practices, if the structure of the power module or
the electric motor is changed, it will be necessary to design a new
pipe for connecting the cooling channels of the power module and
the electric motor in accordance with that change, which will be a
very heavy burden on manufacturing. In this embodiment, however,
even if the structure of the power module or the electric motor is
changed, their cooling channels can be connected by simply changing
the positions on the supporting member 7 at which holes are bored,
since the cooling channel 27 is formed inside the supporting member
7. Hence, it is possible to reduce the burden on designing and
greatly enhance versatility. For example, the positions of the
power-module channel inlet 33 and the power-module channel outlet
35 may just need to be changed if the structure of the power module
25 is changed, and the position of the supporting-member channel
outlet 37 may just need to be changed if the structure of the
electric motor 3 is changed.
Meanwhile, the supporting member 7 may be formed of an elastic
body. This is to prevent deterioration in heat dissipation
performance and water-tightness of the connecting pipe 39 by
deformation of the electric-motor housing 11. Generally, the
electric-motor housing 11 has high rigidity since it needs strength
to withstand in-vehicle conditions. Also, the supporting member 7
needs to be fixed to the electric-motor housing 11 by bolting when
fixed to the electric motor 3. On the other hand, before fixing the
supporting member 7 to the electric motor 3, a step of inserting
the stator of the electric motor 3 in the electric-motor housing 11
by shrink-fitting is performed in consideration of the thermal
endurance of the electronic components. Performing the
shrink-fitting may possibly deform the electric-motor housing 11.
Thus, when the supporting member 7 is fixed, it may possibly need
to be forcibly fixed by fastening at spots with dimensional gaps
resulting from the shrink-fitting. Then, the supporting member 7 is
formed of an elastic body to absorb the deformation of the
electric-motor housing 11 and prevent deformation of the connecting
pipe 39 so that the supporting member 7 will not affect the thermal
transfer and seal performance of the connecting pipe 39 when fixed.
In this way, it is possible to prevent deterioration in heat
dissipation performance, water-tightness, and the like of the
connecting pipe 39.
Further, instead of forming the supporting member 7 from an elastic
body, the supporting member 7 may be thinned at the positions where
it is bolted, and elastic bodies may be disposed there. In other
words, the supporting member 7 may be fixed to the electric motor 3
with elastic bodies interposed therebetween. In this way, an
advantageous effect similar to the case of forming the supporting
member 7 from an elastic body can be achieved more simply.
[Process of Manufacturing In-Vehicle Drive Device]
Next, a process of manufacturing the in-vehicle drive device 1
according to this embodiment will be described. Firstly in the
process of manufacturing the in-vehicle drive device 1 according to
this embodiment, the power conversion unit 5 is mounted on the
supporting member 7. The power module 25 and a group of other
electronic components, for example, a current sensor, a smoothing
capacitor, a control board, and the like are mounted on top of the
supporting member 7, and busbars and harnesses connecting given
components, and the like are attached. In doing so, the cooling
channels of the supporting member 7 and the power module 25 may be
connected by means of face seals or the like. Also, the connecting
pipe 39 may be welded to the supporting member 7.
Usually, handling electronic components requires significantly more
strict control of the inside of the room than handling mechanical
components in order to avoid contamination and static electricity.
In conventional practices, electronic components are mounted
directly to an electric motor, and therefore the electronic
components need to be mounted inside the manufacturing room for the
electric motor. This adds a step that requires measures against
contamination and static electricity to the process of
manufacturing the electric motor.
In this embodiment, however, the electronic components are mounted
on the supporting member 7, and therefore the step of mounting the
electronic components can be performed inside a room other than the
manufacturing room for the electric motor, for example, the
manufacturing room for the inverter. The manufacturing room for the
inverter is originally equipped with measures against contamination
and static electricity and does not require any new measures to be
taken. This prevents addition of a step that requires measures.
Thereafter when exiting the manufacturing room for the inverter,
the supporting member 7 may just need to be covered with a simple
cover to avoid contamination and static electricity. Moreover, in
the manufacturing room for the electric motor, an exclusively
divided small room is prepared, in which the simple cover is
removed and the supporting member 7 is inserted into the housing
portion 19 of the electric-motor housing 11 from above and mounted
thereto. Here, the connecting pipe 39 is inserted into the
electric-motor channel inlet 23 to unite them at the same time as
mounting the entirety. In doing so, water-tightness is ensured
with, for example, shaft sealing (rubber packing) or the like. For
these operations, the operator may first perform positioning and
preparatory operations so that the shaft sealing of the connecting
pipe 39 will be achieved, and then bolt the supporting member 7 to
fix it. Then, the operator lastly bolts the top plate 15.
Consequently, the process of manufacturing the in-vehicle drive
device 1 according to this embodiment is completed.
Advantageous Effects of First Embodiment
As described above in detail, in the in-vehicle drive device 1
according to this embodiment, the power conversion unit 5 is
mounted on the supporting member 7, and this supporting member 7 is
fixed to the electric motor 3. Thus, only the step of fixing the
supporting member 7 may be performed in the manufacturing room for
the electric motor 3. This can prevent addition of a step that
requires measures against contamination and static electricity.
Also, the supporting member 7 includes the cooling channel 27,
which is connected to the cooling channel 21 of the electric motor
3. Thus, even if the structure of the electric motor 3 is changed,
the cooling channels of the electric motor 3 and the supporting
member 7 can be connected by simply changing the position of
connection of the cooling channel of the supporting member 7.
Hence, it is possible to reduce the burden on designing and enhance
versatility.
Also, in the in-vehicle drive device 1 according to this
embodiment, the power conversion unit 5 includes a cooling channel,
and the cooling channel 27 of the supporting member 7 connects the
cooling channel 21 of the electric motor 3 and the cooling channel
of the power conversion unit 5. Thus, even if the structures of the
power conversion unit 5 and the electric motor 3 are changed, the
cooling channel between the power conversion unit 5 and the
electric motor 3 can be connected by simply changing the position
of connection of the cooling channel of the supporting member 7.
Hence, it is possible to reduce the burden on designing and enhance
versatility.
Further, in the in-vehicle drive device 1 according to this
embodiment, the supporting member 7 is formed of an elastic body.
Thus, even if the electric-motor housing 11 is deformed by
shrink-fitting, the supporting member 7 can absorb the deformation
of the electric-motor housing 11. Hence, it is possible to prevent
deterioration in heat dissipation performance, water-tightness, and
the like of the connecting pipe 39 and the like.
Also, in the in-vehicle drive device 1 according to this
embodiment, the supporting member 7 may be fixed to the electric
motor 3 with elastic bodies interposed therebetween. Thus, even if
the electric-motor housing 11 is deformed by shrink-fitting, the
supporting member 7 can absorb the deformation of the
electric-motor housing 11. Hence, it is possible to prevent
deterioration in heat dissipation performance, water-tightness, and
the like of the connecting pipe 39 and the like.
Further, in the in-vehicle drive device 1 according to this
embodiment, the cooling channel 27 of the supporting member 7 is
formed inside the supporting member 7. Thus, even if the structure
of the electric motor 3 is changed, the cooling channels of the
electric motor 3 and the supporting member 7 can be connected by
simply changing the position of connection of the cooling channel
of the supporting member 7. Hence, it is possible to reduce the
burden on designing and enhance versatility.
Second Embodiment
Next, an in-vehicle drive device according to the second embodiment
of the present invention will be described with reference to
drawings. Note that the same constituent components as those in the
first embodiment will be denoted by the same reference signs, and
detailed description thereof will be omitted.
[Configuration of In-Vehicle Drive Device]
FIG. 4 is an exploded perspective view illustrating the structure
of the in-vehicle drive device according to this embodiment. FIG. 5
is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to this embodiment. As
illustrated in FIGS. 4 and 5, an in-vehicle drive device 41
according to this embodiment differs from the first embodiment in
that a supporting-member channel outlet 37 in a supporting member 7
is connected in direct contact with an electric-motor channel inlet
23 in an electric motor 3.
Specifically, in this embodiment, the supporting member 7 is
inserted to the lowest point in a housing portion 19 and fastened
and fixed by bolting at a position where the supporting member 7
abuts the outer periphery of the electric motor 3. In doing so, a
cooling channel 27 in the supporting member 7 and a cooling channel
21 in the electric motor 3 are connected at the same time as
fastening and fixing the supporting member 7, since the
supporting-member channel outlet 37 in the supporting member 7 is
formed at the position where the supporting-member channel outlet
37 faces the electric-motor channel inlet 23 in the electric motor
3. Meanwhile, the supporting member 7 may have the structure
illustrated in FIG. 11.
Here, water-tightness between the supporting-member channel outlet
37 and the electric-motor channel inlet 23 is ensured by means of a
face seal. Moreover, a positioning pin with a locating structure is
provided around the supporting-member channel outlet 37 and the
electric-motor channel inlet 23 to ensure dimensional accuracy at
the face sealing portion.
Advantageous Effect of Second Embodiment
As described above in detail, in the in-vehicle drive device 41
according to this embodiment, the supporting-member channel outlet
37 is connected in direct contact with the electric-motor channel
inlet 23. This can eliminate the pipe for connecting the cooling
channel 27 of the supporting member 7 and the cooling channel 21 of
the electric motor 3. Hence, it is possible to reduce the number of
constituent components.
Third Embodiment
Next, an in-vehicle drive device according to the third embodiment
of the present invention will be described with reference to
drawings. Note that the same constituent components as those in the
first and second embodiments will be denoted by the same reference
signs, and detailed description thereof will be omitted.
[Configuration of In-Vehicle Drive Device]
FIG. 6 is an exploded perspective view illustrating a structure of
the in-vehicle drive device according to this embodiment. As
illustrated in FIG. 6, an in-vehicle drive device 61 according to
this embodiment differs from the first and second embodiments in
that a supporting member 7 is disposed on the outer periphery of a
cylindrical electric motor 3, and the supporting member 7 is fixed
to the electric motor 3 at positions where the distance between the
electric motor 3 and the supporting member 7 is long due to the
cylindrical shape of the electric motor 3.
In this embodiment, a housing portion 19 is not formed in an
electric-motor housing 11; instead, a housing case 63 is provided
to the supporting member 7. This housing case 63 is a box-shaped
protection case that houses electronic components such as a power
module 25 mounted on the supporting member 7, and is placed on the
supporting member 7.
Also, a fastening and fixing portion 65 is formed on the
electric-motor housing 11 for fixing the supporting member 7 by
bolting. This fastening and fixing portion 65 is a pedestal in
which threaded holes 67 are formed.
Note that a cooling channel 27 in the supporting member 7 and a
cooling channel 21 in the electric motor 3 may be connected by
using a pipe as the connecting pipe 39 in the first embodiment or
by connecting an cooling-channel outlet in the supporting member 7
and a cooling-channel inlet in the electric motor 3 in direct
contact with each other, as described in the second embodiment.
Meanwhile, the supporting member 7 may have the structure
illustrated in FIG. 11.
Here, the electric motor 3 has an inner-rotor structure, including
a rotor that rotates as a drive shaft and a stator that generates
rotating magnetic fields for rotating the rotor. The stator is
fixed to the electric-motor housing 11 by shrink-fitting or the
like. The rotor and the stator are both circular in cross section.
Disposing the supporting member 7 on the outer periphery of the
electric motor 3 forms areas where the distance between the
supporting member 7 and the stator is long and areas where the
distance is short. Since the supporting member 7 has a flat plate
structure, the distance to the stator is short at the center of the
supporting member 7 whereas the distance to the stator is long on
the outer side.
Fastening is commonly used as a method of fixing the supporting
member 7 to the electric-motor housing 11 in the case of an
in-vehicle configuration. For the sake of reducing the vehicle
weight, the electric-motor housing 11 is designed to be thin to
such an extent as not to impair its strength. The electric-motor
housing 11 is designed to be thin at, the portion between the
supporting member 7 and the stator, which is not required to have
significantly high strength under the in-vehicle conditions. The
portion between the supporting member 7 and the stator is designed
to be thin also due to a reason that the height of the device in
the state of being mounted on the vehicle is desired to be as small
as possible.
In the case of fixing the supporting member 7 to the electric-motor
housing 11 by fastening, threaded holes are provided in the
electric-motor housing 11 for convenience of manufacturing. In this
case, since the electric-motor housing 11 is thin at portions where
the distance between the stator and the supporting member 7 is
short, making threaded hole there reduces the strength around them,
which may possibly result in a loss of reliability in strength
under the in-vehicle conditions and the stator shrink-fitted
condition. However, the distance between the supporting member 7
and the stator increases from the center of the supporting member 7
toward the outer side thereof. Thus, forming a pedestal as the
fastening and fixing portion 65 by making the electric-motor
housing 11 thick on the outer side of the supporting member 7 can
achieve both the fastening of the supporting member 7 and the
reliability in strength of the electric-motor housing 11.
Alternatively, as illustrated in FIG. 7, the supporting member 7
may be disposed with a space provided between the supporting member
7 and the electric-motor housing 11. Specifically, the height of
the fastening and fixing portion 65 may be increased so as to
provide a space (air layer) between the lower surface of the
supporting member 7 and the upper surface of the electric-motor
housing 11, so that they do not contact each other. The cooling
channel 27 of the supporting member 7 and the cooling channel 21 of
the electric motor 3 may be connected by using a pipe as the
connecting pipe 39 in the first embodiment.
Here, the electric motor 3 generates heat due to the iron loss of
the rotor, the iron loss of the stator core, and the copper loss of
the exciting coils. Moreover, characteristics of the power module
25, the smoothing capacitor, the current sensor, the control board,
and the like, which are electronic components, vary by temperature,
and their heatproof temperatures are lower than those of the
magnets of the rotor, the insulating material of the exciting
coils, and the like. Thus, the electric motor 3 is water-cooled so
that the heat generated by the electric motor 3 will not spread to
its surroundings.
In this embodiment, in addition to the water-cooling of the
electric motor 3, the upper surface of the electric-motor housing
11 and the lower surface of the supporting member 7 are out of
contact with each other by providing a space (air layer). The
presence of the air layer allows less heat transfer and can
therefore reduce the transfer of the heat of the electric motor 3
to the supporting member 7.
Advantageous Effects of Third Embodiment
As described above in detail, in the in-vehicle drive device 61
according to this embodiment, the supporting member 7 is disposed
on the cylindrical outer periphery of the electric motor 3.
Moreover, the supporting member 7 is fixed to the electric motor 3
at positions where the distance between the electric motor 3 and
the supporting member 7 is long due to the cylindrical shape of the
electric motor 3. Hence, it is possible to fix the supporting
member 7 while ensuring the reliability in strength of the electric
motor 3.
Also, in an in-vehicle drive device 71 according to this
embodiment, the supporting member 7 is disposed with a space
provided between the supporting member 7 and the electric motor 3.
This can reduce the transfer of the heat of the electric motor 3 to
the supporting member 7. Hence, it is possible to reduce the
thermal interference between the electric motor 3 and the group of
electronic components.
Fourth Embodiment
Next, an in-vehicle drive device according to the fourth embodiment
of the present invention will be described with reference to
drawings. Note that the same constituent components as those in the
first to third embodiments will be denoted by the same reference
signs, and detailed description thereof will be omitted.
[Configuration of In-Vehicle Drive Device]
FIG. 8 is an exploded perspective view illustrating the structure
of the in-vehicle drive device according to this embodiment, and
FIG. 9 is a cross-sectional view illustrating the structure of the
in-vehicle drive device according to this embodiment. As
illustrated in FIGS. 8 and 9, an in-vehicle drive device 81
according to this embodiment differs from the first to third
embodiments in that a supporting member 7 is fixed such that the
surface thereof on which a power conversion unit 5 is mounted faces
an electric motor 3.
In this embodiment, the supporting member 7 is upside down, so that
the back surface of the supporting member 7 serves as a lid that
seals a housing portion 19. This can eliminate the top plate 15 in
the first embodiment. Also, a cooling channel 27 in the supporting
member 7 and a cooling channel 21 in the electric motor 3 are
connected by a connecting pipe 83. The connecting pipe 83 is
obtained, for example, by extending a bulge attached to the cooler
and mounting shaft seals at the tips, and is disposed outside the
housing portion 19 and connects a supporting-member channel outlet
85 and an electric-motor channel inlet 87. Meanwhile, the
supporting member 7 may have the structure illustrated in FIG.
11.
When the supporting member 7 is mounted, the connecting pipe 83 is
inserted into the electric-motor channel inlet 87 to unite them at
the same time as mounting the entirety. In doing so,
water-tightness is ensured with shaft sealing (rubber packing). For
these operations, the operator may first perform positioning and
preparatory operations so that the shaft sealing of the connecting
pipe 83 will be achieved, and then bolt the supporting member 7 to
fix it. In this way, the connecting pipe 83 can be connected at the
same time as mounting the supporting member 7.
Advantageous Effect of Fourth Embodiment
As described above in detail, in the in-vehicle drive device 81
according to this embodiment, the supporting member 7 is fixed such
that the surface thereof on which the power conversion unit 5 is
mounted faces the electric motor 3. This eliminates components such
as the top plate 15. Hence, it is possible to reduce the number of
constituent components.
Fifth Embodiment
Next, an in-vehicle drive device according to the fifth embodiment
of the present invention will be described with reference to a
drawing. Note that the same constituent components as those in the
first to fourth embodiments will be denoted by the same reference
signs, and detailed description thereof will be omitted.
[Configuration of In-Vehicle Drive Device]
FIG. 10 is a side view illustrating the structure of the in-vehicle
drive device according to this embodiment. As illustrated in FIG.
10, an in-vehicle drive device 91 according to this embodiment
differs from the first to fourth embodiments in that a supporting
member 7 is disposed on a lateral side of an electric motor 3.
In this embodiment, the supporting member 7 is fastened and fixed
to a lateral side of an end plate 13 of the electric motor 3.
Moreover, as in the above-described embodiments, the supporting
member 7 allows a group of electronic components such as a power
module 25 to be mounted thereon, and includes a supporting-member
channel outlet at the back surface. A cooling channel 27 in the
supporting member 7 is connected to a cooling channel 21 in the
electric motor 3 through an electric-motor channel inlet in the end
plate 13. The cooling channels of the supporting member 7 and the
end plate 13 are connected by means of a face seal. Also, the
supporting member 7 is covered by a housing case 93 together with
the mounted power conversion unit 5.
In the other embodiments described above, the supporting member 7
is disposed on the outer periphery of the electric motor 3. Since
the output shaft of the electric motor 3 is parallel to the drive
shaft or propeller shaft of the vehicle, the electric motor 3 is
parallel to the vehicle. For this reason, the supporting member 7
disposed on the outer periphery of the electric motor 3 is disposed
on top of the electric motor 3 in parallel to the vehicle, thereby
increasing the height of the device.
In contrast, in this embodiment, the supporting member 7 is
disposed on a lateral side of the electric motor 3. Hence, the
supporting member 7 is perpendicular to the output shaft of the
electric motor 3 and perpendicular to the drive shaft or propeller
shaft of the vehicle, and is therefore perpendicular to the vehicle
as well. Thus, if the size of the supporting member 7 is within the
height of the electric motor 3, the height of the in-vehicle drive
device 91 is never greater than the height of the electric motor 3.
Accordingly, the height of the in-vehicle drive device 91 can be
kept small.
Advantageous Effect of Fifth Embodiment
As described above in detail, in the in-vehicle drive device 91
according to this embodiment, the supporting member 7 is disposed
on a lateral side of the electric motor 3. Hence, it is possible to
reduce the height of the in-vehicle drive device 91.
It is to be noted that the above-described embodiments are mere
examples of the present invention. Hence, the present invention is
not limited to the above-described embodiments but can be changed
in various ways as modes other than these embodiments in accordance
with the design and/or the like without departing from the
technical idea of the present invention, as a matter of course.
REFERENCE SIGNS LIST
1, 41, 61, 71, 81, 91 in-vehicle drive device 3 electric motor 5
power conversion unit 7 supporting member 11 electric-motor housing
13 end plate 15 top plate 17 reducer 19 housing portion 21, 27
cooling channel 23 87 electric-motor channel inlet 25 power module
29 bottom plate 31 supporting-member channel inlet 33 power-module
channel inlet 35 power-module channel outlet 37, 85
supporting-member channel outlet 39, 83 connecting pipe 51 channel
board 53 supporting board 63, 93 housing case 65 fastening and
fixing portion
* * * * *